Sony SONY XAV-AX8500 from Trail Grid Pro - No back up cam on screen

Help Grandpa with his system. I emailed Trail Grid Pro Customer Support and they said they did not know how to do it.

I bought their system and installed it in my 2013 DC. I have the factory back up cam in my rear view mirror. Non JBL. No NAV in stock radio. Just replaced the stock AM/FM multiCD radio.

SONY XAV-AX8500 plays great with radio and makes stock speakers sound awesome.

BUT, I plugged everything they sent into the plugs on my wiring harness. When I put it in reverse it does not show on my new screen. Says something like no source found.
I tried searching this site and could not find any threads for "Sony" or "Backup cam" that address this specific issue.

Is there a way to wire the factory backup cam that displays in my rear view mirror to show up on my new radio screen?

 

I'm not exactly sure what would be needed, but I believe this is the applicable portion of the wiring diagram for your year/configuration. The full audio/video diagram can be found here: All Years Complete Audio System Wiring Diagrams | Toyota Tundra Forum (tundras.com) and the full 700+ page electrical diagrams can be found here: Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)


The top blue portion represents your radio, and the bottom blue portion represents (I think) your rear view mirror with the built in back up cam screen.
I'm no electrical engineer so take this with a grain of salt, but to me it looks like the signal from the backup camera must go into the factory radio which acts like a junction point, and then the signal goes from the factory radio up to the rear view mirror monitor. Unhooking the connector going to the mirror is where'd I'd start and then you could use a multimeter with piercing probes to test these 4 wire colors as I'm not exactly sure what the abbreviations mean. I'm guessing CB+ and CGND are the power and ground for the camera, and CV+ and CV- are the positive and negative for the signal of the camera, or vice versa. Your other option would be to replace the factory tailgate handle and rear view cam with a newer/better one and run a new wire loom from the tailgate into the cabin and up to the stereo. Your new stereo also has additional camera inputs so you could add a front camera super easily while you're at it. I added a front camera on my 2021 with a Sony XAV-9000 and it's actually a worthwhile mod in my opinion, makes parking a no brainer.

After typing all that I was googling and came across this Five Star Car stereo video that's a much more in depth and better explanation of what I was getting at, eureka! Watch this and it should answer any questions on how to do this using your existing cam.
How to move your factory Toyota Mirror Camera to your new radio (youtube.com)

 

This may or may not help.
There may be a video feed plug in your driver's side A pillar.
Is it possible or not? Camera to HU | Toyota Tundra Discussion Forum (tundratalk.net)

 

His camera system may be aftermarket and have no connection to the HU at all.

2010 - 2013 Tundra® OEM Camera Kit, Gentex® 3345 Homelink® Mirror - Camera Source Backup Cameras

 

@Snert, @1lowlife - you guys are certainly very helpful! I'm sure we all appreciate you.

 

I was actually looking at Camera Source to see if they sold a wiring harness or adapter specifically for this purpose lol but yeah I didn't consider his system might not be OEM, good call. Other option I forgot to mention would be reaching out to AutoHarnessHouse and see if they can rig up a plug and play harness with a RCA lead to go down to the new head unit.